Field of the Invention
The present invention relates generally to mobile stations, and more specifically to preserving battery power in mobile stations.
Cellular telecommunications is one of the fastest growing and most demanding telecommunications applications. Today it represents a large and continuously increasing percentage of all new telephone subscriptions around the world. A standardization group, European Telecommunications Standards Institute (ETSI), was established in 1982 to formulate the specifications for the Global System for Mobile Communication (GSM) digital mobile cellular radio system.
With reference now to FIG. 1 of the drawings, there is illustrated a GSM Public Land Mobile Network (PLMN), such as cellular network 10, which in turn is composed of a plurality of areas 12, each with a Mobile Switching Center (MSC) 14 and an integrated Visitor Location Register (VLR) 16 therein. The MSC 14 provides a circuit switched connection of speech and signaling information between a Mobile Station (MS) 20 and the PLMN 10. The MSC/VLR areas 12, in turn, include a plurality of Location Areas (LA) 18, which are defined as that part of a given MSC/VLR area 12 in which the MS 20 may move freely without having to send update location information to the MSC 14 that controls the LA 18. Each LA 18 is divided into a number of cells 22. The MS 20 is the physical equipment, e.g., a car phone or other portable phone, used by mobile subscribers to communicate with the cellular network 10, each other, and users outside the subscribed network, both wireline and wireless.
The MSC 14 is in communication with at least one Base Station Controller (BSC) 23, which, in turn, is in contact with at least one Base Transceiver Station (BTS) 24. The BTS 24 is the physical equipment, illustrated for simplicity as a radio tower, that provides radio coverage to the cell 22 for which it is responsible. It should be understood that the BSC 23 may be connected to several BTS""s 24, and may be implemented as a stand-alone node or integrated with the MSC 14. In either event, the BSC 23 and BTS 24 components, as a whole, are generally referred to as a Base Station System (BSS) 25.
With further reference to FIG. 1, the PLMN Service Area or cellular network 10 includes a Home Location Register (HLR) 26, which is a database maintaining all subscriber information, e.g., user profiles, current location information, International Mobile Subscriber Identity (IMSI) numbers, and other administrative information, for subscribers registered within that PLMN 10. The HLR 26 may be co-located with a given MSC 14, integrated with the MSC 14, or alternatively can service multiple MSCs 14, the latter of which is illustrated in FIG. 1.
Each MS 20 is powered by a rechargeable battery. These batteries retain their charge for only a limited period of time. When the battery life has expired, the mobile subscriber must recharge the battery in order to continue using the MS 20. In many cases, it may be important for a subscriber to prolong the battery life of the MS 20 as long as possible. For example, if the subscriber is traveling in a remote area where sources of electricity are sparse, the subscriber may not be able to recharge the battery when the battery life expires. This may result in missed important calls.
In these situations, the only option for the subscriber is to turn off the MS 20 in order to preserve the battery life. However, if the MS 20 is simply turned off, the subscriber has no ability at all to make or receive calls. In addition, even if the MS 20 is turned off, the battery is still being depleted, although at a lower rate. For example, a sample MS 20 battery may have the following battery life specifications: talk time: 3 hours; stand-by mode with MS 20 power on: 170 hours; stand-by mode with MS 20 power off: 600 hours. Therefore, even if the MS 20 is simply turned off, the battery will still be depleted in 600 hours.
In addition, if the MS 20 is turned off, the subscriber will not be able to make or receive calls or send or receive short messages. Furthermore, calling parties attempting to reach the mobile subscriber with a powered off MS 20 have no way of knowing if or when the mobile subscriber may turn the MS 20 back on. Therefore, the mobile subscriber with the powered off MS 20 may also miss important calls by attempting to preserve the battery life.
The present invention is directed to telecommunications systems and methods for extending the life of a battery within a Mobile Station (MS), while still allowing a mobile subscriber to use the MS. A new battery gapping feature can be implemented within both the MS 20 and the cellular network. On the MS side, the feature will allow the subscriber to select the desired battery gapping mode, which is a combination of the stand-by mode with the MS power on and the stand-by mode with the MS power off. When in this battery gapping mode, the MS will alternate between power off and power on states depending upon the subscriber defined stand-by times for each of these states. On the network side, the MS will inform the network when the MS powers off, as well as indicate when the MS will be powered on again. Therefore, the network can inform calling parties that place incoming calls to the MS during the time that the MS is powered off of the reason the call is rejected and the next time that the MS will be reachable. In addition, the mobile subscriber can also define a maximum amount of talk time for each incoming call while the MS is powered on, but in battery gapping mode.